Python Programming for Degree Heating Weeks Estimation using Sea Surface Temperature Data from The Google Earth Engine Dataset as Coral Bleaching Analysis Tools

Abstract

Abstract This study aims to develop a program to calculate Degree Heating Weeks (DHW) using Python programming and Sea Surface Temperature (SST) data available in Google Earth Engine (GEE) datasets, e.g., HyCom, NOAA OISST v2.1, MODIS-Aqua, and NOAA Pathfinder v5.3. This study contributes to providing a DHW calculator currently unavailable on the Internet to analyze coral bleaching. This program is called PyDHW. The DHW was calculated by inputting the desired location in a polygon, a specific time range, and the SST data. The results show that Python code can extract SST from the GEE dataset according to the user’s input. This SST data is the average of the SST inside the polygon area. This program calculates and shows a graph of the DHW showing coral bleaching alert levels. All these processes were performed quickly in one run. HyCom and NOAA OISST v2.1 have a long and continuous data range. NOAA OISST v2.1 is still updated in the GEE dataset rather than the others. The MODIS-Aqua contains blank time-series data for several measurements. The NOAA Pathfinder v5.3 data shows extreme change in time series data and low temperatures with different patterns from the other SST data. However, this program is still under development and needs improvements. This program is expected to help users concerned with coral research and monitoring.